


To the brim

by k_cloud



Category: Supernatural
Genre: Alpha Sam Winchester, Anal Sex, Barebacking, Cockslut Dean, Come Inflation, Hair-pulling, M/M, Omega Dean, Omega Dean Winchester/Alpha Sam Winchester, Oral Sex, Rough Sex, Sibling Incest, Size Difference, Size Kink, Supernatural Kink Meme, brief Dean/OMC, monster cock
Language: English
Status: In-Progress
Published: 2020-03-11
Updated: 2020-03-11
Packaged: 2021-02-23 03:54:47
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,108
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23105287
Author URL: https://archiveofourown.org/users/k_cloud/pseuds/k_cloud
Summary: Anything with Dean being a slut for 15-16yo Sammy's cock, Dean can't go more than a couple of days without his baby brother's cock in his ass or his mouth and he always comes harder when Sam pulls his hair.No scat or spit kink. A/B/O is fine but no mpreg please.https://spnkink-meme.livejournal.com/156863.html?thread=47501503#t47501503
Relationships: Dean Winchester/Sam Winchester
Comments: 14
Kudos: 388
Collections: Supernatural Kink Meme





	To the brim

Dean hasn't always been a slut for his little brother's cock.

It all started when Dean was 18. He remembers it because it was the day of his birthday. John took the two of them out for burgers to celebrate. Once they got home, full and strangely cheery, Dean couldn't sleep.  
He laid on his bed, tired but awake, listening to sounds of the house.  
He was almost asleep when he heard it; a hitching of breath, a shuffling of sheets, and a rhythmic slapping sound.  
it was way too easy to just quietly turn towards the sound.  
What he saw changed everything.

Little 15 year old Sammy, jacking off an enormous cock. It was disproportionate, thick and long and almost looking misplaced on his lanky teenage body.  
Dean watched on, his own cock hardening in his boxers, unable to tear his eyes from the sight.  
Because Sam's cock was red and shiny, the fat mushroom head slipping in and out of his fist, wet and glistening with precum. It curved a little and it was so thick Sam's hand barely fit around it, his fingers barely touching around the veiny cock.  
Dean couldn't even see the whole thing, his view partially hidden by Sam's underwear.  
He wondered what Sam's balls looked like.  
He knew Sam hadn't presented yet, but with a cock like that there was no doubt he'd be an alpa in only a matter of time.  
Dean wanted nothing more than to reach out and pull his boxers all the way down, expose him fully and suck the whole thing into his mouth, and then taste the bitterness right on his tongue.  
He laid there, paralyzed and rock hard, slick oozing freely out of his aas, unable to move as he watched his little brother fist his huge dick.  
Sam didn't take that long to come, rutting in his fist and biting his lip until his cock finally erupted all over his shirt.  
There was so much cum. Spurt after spurt after spurt, thick and heavy and Dean whined a little thinking of how much more there would be once Sam popped his knot. Once Sam fell back asleep, exhausted by his orgasm, Dean replayed the images in his head and rutted his own tiny cock against the mattress until he came. The shame he felt immediately after wasn't enough to dampen the afterglow.

Dean didn't think about anything else for days. Wanking off in the shower any chance he got, stuffing as many fingers as he could in his aching ass.  
Nothing felt like enough, and a few very horny days later he found himself going to a club and propositioning the biggest baddest alpha he could spot and letting him fuck him in the club bathroom. the guy was massive, over forty and with thick, bulging muscles, the exact opposite of Sam's lanky body. He pinched his nipples just the way Dean liked, and the rough pounding he received was enough to put Sam's cock out of his mind for a few days.  
"you're such a slut for my knot" the alpha said, pistoning his hips in and out of Dean's ass, and Dean agreed, grateful.

It went on like that for a whole year, Dean lusting after his little brother's cock, getting wet every single time he caught sight of Sam wearing sweatpants or basketball shorts, or adjusting himself with his legs spread wide.  
He ended up convincing John to let him sleep in the basement, so he could at least be away from having that glorious temptation lying just feet from him every night.  
It worked well enough, Dean always felt like there was something missing, but frequent knots and burly alphas kept him from acting on his ridiculous desire.

the second time it happened, it again happened by chance. Dean went to a new club, fully intending to find some new alpha to knot him and sate the urge for a while. But once he got there he quickly realized it was only frequented by young guys, all slim hips and long arms, that reminded him of Sam way too much.  
So he went home, thinking he could maybe sneak his dildo in the shower and fuck himself with it while John and Sam slept.  
Once he got home though, his plans completely flew out of the window.  
Sam was sprawled on the couch, naked from the waist down, his fist now still on his very much erect cock. Moans filled the room as the porn Sam was clearly in the middle of watching, kept on going on the TV screen.  
Dean knew he should have said something or at least cover his eyes, but he couldn't help himself but staying glued to the picture of that magnificent cock, veiny and red and shiny with lube.

"Didn't expect you to be home so early" Sam said. His hand picked up a slow pace up and down his dick, like nothing happened.  
Dean couldn't find anything to say.  
"You can join me if you want, this is a good one, Brady showed me" Sam said, turning back to where two hairy alphas were spitroasting a twink on the screen.

Dean knew he should say no, but his hole already felt so empty and so needy, oozing slick and clenching around nothing, so he gave in.  
He sat next to Sam on the couch and tried to make himself watch the screen instead of his own brother's cock.  
The men on the screen were really going at it, and Sam's hand was speeding up on his dick. he needed both hands to rub it from root to tip, and this time Dean got to see the whole thing in all its Glory, including Sam's hairy balls. They were huge, definitely soon-to-be-alpha balls, and Dean just knew they'd make an amazing slapping sound smacking against his ass.  
He moaned at the thought and finally took out his own tiny dick so he could frantically jerk off.  
It looked pathetic compared to Sam's, must have been 3 inches, compared to Sam's 14 and the difference made it all so much hotter.  
He rutted fast into his palm, and he didn't even realize he wasn't even watching the TV anymore.

"You can touch it if you want" Sam said suddenly, a smug smirk on his face.

Dean was speeches. "T-touch it?" he said

"Yeah, I can see how badly you want it, you keep looking at it. It's an Omega thing I think, Brady can't keep his eyes off it either when we jerk off together. I don't mind" he shrugs, completely shameless.

Dean wasn't about to walk out of this wet dream so he curled a hand on Sam's cock and started jerking him off, trying to focus on that monster cock only and not the person it belonged to.  
"Tighter" said Sam after a while, pushing his hips into Dean's hand impatiently.

Dean obeyed, trying to sqeeze his fingers around Sam's member at best as he could.  
It felt glorious under his palm so smooth and hot, and Dean was hypnotized by the sight of that fat shiny head popping in an out of his fist.  
"Always wanted to do that, but Ruby said my dick is too big for it" Sam sighed as looked at the screen. one of the alphas was shoving his fat cock down the omegas throat, so deep they could see the outline of it in the poor guy's throat.  
Dean's brain short circuited with the picture of Sam being the one doing that to dainty Ruby. Doing that to him. fuck. If he could only get a taste of Sam's cock he knew he'd never let it go.

"it's not too big" Dean said, as he used his other hand to tug at Sam's huge balls.  
Sam groaned and a fat drop of precum oozed out of his cock all the way down to Dean's hand. Dean really wanted to taste it in his mouth, so he whined and felt his ass drip with even more slick.

"Yeah, wanna prove that, Dean?" Sam rebutted, like he knew how badly Dean wanted it.  
Dean knew he shouldn't give in, but be did anyways.

He knelt in between Sam's legs, and then dived in like he was in front of a banquet made out of pies only.  
He sucked Sam's balls in his mouth, and they were so big he had to stretch his jaw to accommodate them. Sam moaned in satisfaction and Dean felt proud of himself so he kept going.  
He followed the thick veins on Sam's cock with his tongue, fisting a hand on the base while his mouth got all the way to the top.

"come on, you know you wanna taste it" Sam said, lowering a hand on Dean's head and pushing him towards his cock again. Being manhandled like that sent a jolt of arousal straight to Dean's cock and he moaned.  
finally he was able to fit his lips around Sam's cock. It felt huge and smooth and Dean's tongue dived into the slit to lap at as much precum as he could. It tasted bitter and heavenly on his tongue, just like an alpha would.  
Sam groaned and tigthened his fingers in Dean's hair so Dean redoubled his efforts, licking and sucking at that fat head, trying to squeeze as many drops out of it as possible.

"Deeper. I need-" Sam asked, and Dean didn't even let him finish the sentence before he forced his jaw as wide as it would go and started swallowing Sam's cock down.  
It felt huge and almost endless, filling his troat fully as he chocked around the girth.  
When his nose finally hit Sam's pubes he could feel how deep his little brother was inside of him, and he almost came untouched right then.  
He pulled back just enough to get a breath in, before diving right back in, slurping and gagging and losing himself in the pleasure of having one of his holes filled so good, being a good Omega.

At one point Sam put both his hands on Dean's face and started fucking his face in earnest, his balls slapping against Dean's chin and making a delicious sound.  
"Fuck Dean. Fuck. It feels so good. Taking me so deep. Fuckfuckfuck." Sam started speeding up, barely letting Dean take a full breath in as he shoved that giant cock in his throat over and over again.  
Dean started floating a little, as he sat there just taking it.

Finally, after a few more minutes of rough face fucking, when Dean started feeling light headed from the lack of air, Sam came.  
"Gonna do it. Gonna cum right down your slutty throat. that's what you want -fuck- isn't it. A big fat load of your little brother's spunk. here it comes. fuckin take it. take it. ahhhhhhhhh." Sam yelled as he shoved Dean's head in his groin and emptied his balls right down dean's throat. Dean felt it slide hot down his throat and felt sad he couldn't taste all that glorious cum on his tongue.  
He humped the front of the chair a little and his little cock erupted too, his orgasm in time with Sam's.  
Sam kept him there, until he had fully emptied himself, then he finally slid back.  
Dean cleaned Sam's cock with his tongue, reluctant to let it go.

"You were right. it did fit." Sam concluded, his softening cock slapping against his belly.  
Dean laughed. He realized having his brother's cock down his throat didn't mean things had to change. Sam was still the silly 16 year old he had been that morning, and Dean would keep taking care of him as long as he'd have him.  
"Bet there's other places it'll fit" Sam added, his foot moving between Dean's legs to poke at his hole through his pants.  
"So wet for me already." Sam said and Dean let himself grind his asshole back on Sam's foot for a second, feeling shameless.

They didn't do more that night, and after two mere days of trying to pretend he wanted nothing more than to let his little brother wreck his asshole, Dean gave in.  
He showered and then padded to Sam's room in nothing but a towel.  
Sam was sitting at his desk, doing homework, when Dean got in.  
He didn't have to say anything, because as soon as Sam caught sight of him, a wolfish grin spread on his face.

"the little omega coming around for a taste?" he asked, hand sneaking down to palm at his hardening cock.  
Dean didn't even protest, didn't even point out Sam was the younger one and wasn't an actual aplha yet.  
He just kneeled in front of his little brother and sucked his half hard cock in his mouth until it was hard enough to pound nails and he started chocking on the length.  
Sam let him suckle on the cockhead a while, so Dean could get his fill of having his mouth stretched as Sam's cock rested on his tongue.  
He used his foot to undo the towel around Dean's waist and Dean didn't even flinch when his own erect cock was exposed to the air.  
"you're so hot for it, aren't you Dean" Sam teased "alright, on the bed" he ordered eventually and Dean scrambled to comply, immediately folding himself into a presenting position, ass in the air and head bent down low.  
Sam gave an appreciative smack on his ass, before fitting two fingers inside of him roughly.  
Dean moaned.

"sucking my fingers right in. Don't even need much prep, do you?" Sam said, scissoring his fingers inside Dean, before thrusting in a third.  
Dean shoved back on his fingers, already high with the feeling of having something filling his ass.

"Please Sammy" he begged and then Sam's blunt cockhead was at his entrance and Dean choked on his breath. That fat cockhead pressed in, sliding easily into his wet hole.  
Once he breached his hole, Sam just didn't stop, his length pushing and pushing, and Dean felt like he was being speared by a deliciously hot and thick rod.  
it felt like forever before Sam finally bottomed out, Dean's asshole squeezing and massaging his length, trying to coax his cum right into his womb.  
"Fuck" Sam said, as his balls nestled against Dean's skin.

Dean wanted to agree with the sentiment, but all his focus was on breathing around the delicious burn deep into his ass. Sam's cock was so deep Dean could feel it in his belly.  
Sam didn't give him much time to adjust, soon sliding his hips back and dragging his cock in and out of Dean's hole.  
The firsy time Sam slammed his hips back in, shoving Dean's body forward on the bed, Dean immediately knew he'd never find another cock that would compare to his little brothers.

"more sammy, please" he begged, breathless and he didn't need to ask twice.  
Sam snapped his hips back and then slammed back in, his balls slapping against Dean.

"Fuck, Dean, it feels so good. you should see how good your hole looks. all stretched out around my cock" Sam said and dotted his sentence with a sharp snap of his hips that made Dean whimper with how good it was. "you're taking me so good Dean, you're such a good slut for my cock, aren't you."  
And Dean couldn't help but agree as he pushed his hips back to take in as much as Sam's cock as he could.  
"Look at that, fucking yourself on my cock like a bitch in heat." Sam moaned and the hands thay were gripping Dean's hips suddenly pushed at his shoulders and Dean faceplanted on the bed, his balance lost.

Sam lowered his body to cover Deans, pushing him down, pinning him on the mattress and fisting his hand in Dean's hair, so all Dean could do was lay helpless under his as he plowed his asshole.  
Sam seemed to really like this position, because he started grunting loudly and shoving his cock into Dean faster and harder, the hand on Dean's head tightening to the point of delicious pain.  
Dean could barely breathe with the weight of Sam's body on his back, but the new position made it so that his little cock could rest on the comforter. The jolt of pleasure at the contact combined with the weight of Sam's cock in his ass and the burn of Sam's hands pulling his hair, was enough to make him hump the bed once, twice, and then he was coming, his jizz spraying everywhere as his body was jostled around by Sam's wild thrusts.

"Fuck yeah, come on my cock" sam yelled, pulling out for a moment and then slamming his whole cock back in so hard Dean felt it in his stomach.  
Dean could feel his channel tightening rhythmically around Sam's cock, as much as he already felt stretched to the max. He blacked out a little, not being able to focus on anything but how wide his cheeks were spread and how awesome Sam's cock felt inside of him.

"Gonna come, Dean, gonna dump all my cum inside your slutty asshole. fuck. I gotta come" Sam groaned, and Dean was nothing but a ragdoll for him to fuck into by that point, but he whimpered in agreement anyways. Dean loved nothing more than having his belly bulging with a load of alpha cum; he had started taking the pill as soon as  
he figured out how to get an alpha to shove his knot inside him so he wasn't worried about Sam's spunk getting him pregnant.  
Sam's hand tightened even more on his head and Dean ground against him and squeezed his asshole as best as he could, trying to squeeze the cum right out of Sam's cock.

Sam wailed as he came, and Dean felt the hot spunk bursting out of Sam's cock and filling him deep inside. He could barely breathe with Sam's weight pushing him in the mattress, all he could do was focus on the glorious, thick spurts coating his insides. He pictured what it would feel like to squeeze around Sam's knot and the mental picture was enough to send him spiralling into a second orgasm of his own.

Sam took a long time to empty his balls, his orgasm not as long as an alpha's but longer than any unpresented 16 year old had a right to be. Dean was pleasantly surprised to feel his belly plump up with all the come his little brother was pumping inside him.

Once Sam was done cumming, he slowly pulled out of Dean's wrecked asshole. Dean did his best to clench and keep all that hot cum inside, but his asshole had been stretched beyond belief, and some cum came trickling out.  
"Fuck, look at it gaping. it's like it wants me back inside already" Sam observed, stuffing a finger inside Dean and pushing the spunk back in.  
Dean moaned, the thought of being stuffed full over and over again and overwhelming one.  
"That what you want Dean? Sit on your brother's cock all day long and be a good slut?"  
Sam kept going, his fingers pushing in and out of Dean's stretched asshole with a squelching sound.

"Here, you should have a taste" Sam said, then presented Dean with a scoop of still warm come right in front of his mouth.  
Still shaken by his orgasm and somehow still unbelievably turned on, Dean eagerly reached out and sucked his fingers clean, tasting the deliciously bitter cum on his tongue.

"Fuck. None of the girls at school even wanna swallow." Sam sounded surprised and excited and Dean redoubled his efforts. He was surprised nobody was willing to suck Sammy's awesome cock in their mouths, but he was also grateful he was the one who got to show him how good it feels.

"Here. Clean my cock too." Sam said, shuffling on the bed so that his cock was right in front of Dean's mouth, and Dean didn't have to hear him say it twice. Still spread out on the bed, he dived right in, and licked and sucked at it until Sam's cock was clean again. The quickly drying cum tasted weird in his mouth, but the feeling of Sam's soft cock filling his mouth so good was worth it.  
Dean didn't stop once Sam was clean, instead he kept suckling on his cock until it was rock hard and huge again. Choking on Sam's length he couldn't help but fewl grateful for the teenager's refractory period.

"Fuck me Sammy. Please." he begged, as Sam humped his face with his cock, leaving precum smears everywhere.

"I'll fuck you." Sam said, moving so he could sit up against the headboard "But you gotta do all the work, I'm tired" he smirked, fisting his dick, knowing Dean wouldn't be able to take his eyes off it.  
At the request, Dean immediately scrambled to comply and he kneeled over Sam, back to his front. He had to push up on his knees to fit Sam's cock to his asshole.  
Once there, he popped the huge head back inside, and he was about to slowly sit himself on the lenght, when Sam's hands gripped his waist and roughly slammed him all the way down.

Dean yelled, the breath being punched out of his lungs as that huge cock fit all the way inside him in one rough go.  
"Get on with it" Sam said, pinching his flank.  
Sam's cock was so deep inside, it felt like Dean's organs has shuffled around to make room for it. He looked at his belly and he imagined he could see the outline of thag cock deep inside him.

Knowing Sam was impatient, Dean went right for it, slamming his body up and down and grinding in Sam's lap whenever he was fully seated. Sam's cock somehow felt even bigger in that position, and Dean felt even more desperate for it as he frantically bounced on his little brother's big cock, his own little dick hard again and slapping back and forth on his belly.  
Sam kept his word, didn't lift his hips to help Dean out at all, just laid there as Dean desperately impaled himself on his cock over and over again.  
He kept on a continuous stream of filthy talk that drove Dean mad with lust.  
"You're such a slut, big brother. sucking my cock right inside, look at that" he said, slapping Dean's ass roughly, "You want it so bad, don't you. Need ro get that slutty hole all filled up. Fuck, it's gonna be gaping once I'm done with you. No alpha's gonna want such a wrecked asshole anymore."  
Dean just moaned helplessly, because it was true, he would happily give up all those random alphas just for one more minute with Sam's cock all the way inside.  
Too turned on to think, Dean reached a hand towards his cock, wanting so desperately to just come already.

"Stop that" Sam said, slapping his hand away "You're coming on my cock like a good Omega should." and he slammed his hips into Dean.  
Almot feral then, he started pumping into Dean's ass as fast and hard as he could, his massive cock splitting Dean open with every thrust. He fisted a hand into Dean's hair, pulling roughly and making him arch his back. The burn of Sam's nails on his scalp only accentuated the pleasure Dean was feeling.  
He wailed, unable to think of anything other than the forceful thrusts of his little brother under him and his hands on his skin.  
Sam planted his feet on the mattress and drove into Dean's ass even harder.  
"You can come now, Omega" he said, and Dean instantly obeyed. His little cock erupted all over his own belly, as he did his best to ground back against Sam, his insides clenching around his massive cock and trying to milk it.  
It seemed to work, because just a second after Sam was shouting and shoving his cock as deep as it would ever go, as thick, hot, cum painted Dean's insides once more.  
It went on for a while again, and once Sam was done, Dean looked down at his belly and saw it bulging and distended, full with two loads of his brother's hot cum.  
The sight alone almost made his dick hard again.  
Fuck. He really couldn't wait for his little brother to pop a knot and fuck him silly.

**Author's Note:**

> Planning on adding a few more scenes, would love to hear what you think.


End file.
